1. Field of the Invention
The present invention relates generally to the field of communication devices and, more specifically, to speakerphones.
2. Description of the Related Art
Speakerphones may be used to mediate conversations between local persons and remote persons. A speakerphone may have a microphone to pick up the voices of the local persons (in the environment of the speakerphone), and, a speaker to audibly present a replica of the voices of the remote persons. While speakerphones may allow a number of people to participate in a conference call, there are a number of problems associated with the use of speakerphones.
The microphone picks up not only the voices of the local persons but also the signal transmitted from the speaker and its reflections off of acoustically reflective structures in the environment). To make the received signal (from the microphone) more intelligible the speakerphone may attempt to perform acoustic echo cancellation. Any means for increasing the efficiency and effectiveness of acoustic echo cancellation is greatly to be desired.
Sometimes one or more of the local persons may be speaking at the same time. Thus, it would be desirable to have some means of extracting the voices of the one or more persons from ambient noise and sending to the remote speakerphone a signal representing these one or more extracted voices.
Sometimes a noise source such as a fan may interfere with the intelligibility of the voices of the local persons. Furthermore, a noise source may be positioned near one of the local persons (e.g., near in angular position as perceived by the speakerphone). Thus, it would desirable to have a means for suppressing noise sources that are situated close to talking persons.
It is difficult for administrators to maintain control on the use of communication devices when users may move the devices without informing the administrator. Thus, there exists a need for a system and mechanism capable of locating the communication devices and/or detecting if (and when) the devices are moved.
The well known proximity effect can make a talker who is close to a directional microphone have much more low-frequency boost than one that is farther away from the same directional microphone. There exist a need for a mechanism capable of compensating for the proximity effect in a speakerphone (or other communication device).
When a person talks, his/her voice echoes off of acoustically reflective structures in the room. The microphone picks up not only the direct path transmission from the talker to the microphone, but the echoes as well. Thus, there exists a need for mechanisms capable of canceling these echoes.
A speakerphone may send audio information to/from other devices using standard codecs. Thus, there exists a need for mechanisms of capable of increasing the performance of data transfers between the speakerphone and other devices, especially when using standard codecs.